Hi, this is my first lab in 2nd semester of chemistry, and im not sure about my answers in the assignment can someone give it a quick look to check them?
this is my phase diagram:
tinypic. com/view.php?pic=1605yev&s=7
p.s. ignore the lone red dot its supposed to be 38C..
there were the questions:
Mass of lauric acid (from balance): 1.00 g
melting point of lauric acid (from excell): 42.5C
mass of benzoic acid (from balance): 0.246g
melting point of lauric acid/benzoic acid mixture: 34.0C
^Tf= (3.9 C/m)(0.246g/mol) / 0.001 = 959.4
Molecular mass of benzoic acid from calculations: 0.9594/0.0085=112.9
molecular mass of benzoic acid: (given by teacher) 122.2g/mol
%error= 959.4-122.12 / 122.12 X 100 = 690%
Im not sure about the percent error if i used the right numbers. can someone please help? i want to get a good grade on this assignment and its due Wednesday...
If i could just know if the percent error is correct that would be great, that's the one im most unsure of..
To calculate the percent error in this case, you need to compare the experimental value (the calculated molecular mass) to the accepted value (the value given by the teacher). Here's the correct calculation:
Experimental value: 959.4 g/mol
Accepted value: 122.2 g/mol
Percent error = ((Experimental value - Accepted value) / Accepted value) * 100
Percent error = ((959.4 - 122.2) / 122.2) * 100
Percent error = (837.2 / 122.2) * 100
Percent error = 685.4%
So the correct percent error is 685.4%. It seems like there was a slight error in your calculation.
To determine the percent error, you need to compare your calculated value with the accepted value and then calculate the percent difference.
Let's go through the steps for calculating the percent error:
1. Start with the formula for percent error: Percent Error = (|Measured Value - Accepted Value| / Accepted Value) * 100.
2. Plug in the values you have:
Measured Value: 959.4
Accepted Value: 122.2
Using these values in the formula, we have:
Percent Error = (|959.4 - 122.2| / 122.2) * 100
3. Calculate the difference between the measured value and the accepted value:
|959.4 - 122.2| = 837.2
4. Plug the calculated difference and the accepted value into the formula:
Percent Error = (837.2 / 122.2) * 100
5. Calculate the final value:
Percent Error = 685.0%
Therefore, the percent error is approximately 685.0%. It appears that there was a miscalculation in your initial calculation. Please double-check your calculations to ensure accuracy.